Partial characterization of a thyroid-stimulating hormone-like peptide in neuroendocrine cells of the human prostate gland.

Immunohistochemical identification of the most prevalent type of neuroendocrine (NE) cells in the human prostate gland can be made with polyclonal antisera against human thyroid-stimulating hormone (TSH). A TSH-like peptide was characterized by analysis of prostatic tissue homogenates with sodium dodecyl sulfate-polyacrylamide gel (SDS-PAGE) electrophoresis followed by immunoblotting. A single protein band, with an apparent mass of about 32 kDa after reduction, was identified both with polyclonal antisera against human TSH and with a polyclonal antiserum raised against a synthetic peptide corresponding to the carboxyterminal part of the beta-subunit of human TSH. The TSH-like prostatic peptide identified here is, on the basis of its molecular mass and absence of immunoreactivity with an antiserum raised against a synthetic peptide representing the mid-portion of the beta-subunit of TSH, not identical with the pituitary beta-subunit of TSH. On the other hand, this 32 kDa prostatic peptide may have certain structural elements in common with the pituitary beta-subunit of TSH, since it is recognized both with polyclonal antisera against TSH and with an antiserum against the carboxyterminal part of the beta-subunit of TSH.